<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
         /* 响应式原理,通过媒体检测屏幕的大小,改变盒子的大小 */
        .noe{
            width: 1000px;
            height: 400px;
            background-color: aqua;
            display: flex;
            flex-wrap: wrap;
        }
        .noe>div{
            width: 25%;
            height: 400px;
            background-color: beige;
        }
        .noe .two:nth-child(2n){
            background-color: brown;
        }

        @media (max-width:992px) {
            .noe>div{
                width:50%;
            }   
        }
        @media (max-width:768px) {
            .noe>div{
                width:100%;
            }   
        }
    </style>
</head>
<body>
    <div class="noe">
        <div class="two">1</div>
        <div class="two">2</div>
        <div class="two">3</div>
        <div class="two">4</div>
    </div>
</body>
</html>